jkh@jade.UUCP (05/28/86)
Article: 5:19
Newsgroups: mod.rec.guns
I recently acquired a Thompson Auto Ordinance .45 (1911 A1).
Unfortunately, the first trip to the range revealed problems with
ejection of spent casings, finally culminating in the slide/barrel
locking up completely. Is this sort of thing common in .45s? I
would also like to know what sort of mods people have had done to
their .45s to improve feeding, accuracy, etc. On the whole, I think
I'll really like it once I get the bugs sorted out.
-- Carl Kuck
Ejection malfunction in M1911 pattern pistols is most often the
result of insufficient rearward slide travel. This is usually
caused by underpowered ammunition, too strong a recoil spring,
burrs on the slide or frame, or a broken or ill-fitting recoil
spring guide. It can happen if the lockwork breaks and
the hammer jams in the half-cock position.
Ejection malfunction can also result from a loose or broken
extractor, or a loose, missing or broken ejector. Ejection
difficulties may in fact be feeding difficulties caused by a bad
magazine, or by failure to make finishing cuts in the extractor, the
barrel hood or the feed ramp. Finally, feeding difficulties can be
caused by using SWC ammo with stock M1911 chamber throating.
1. First, clear the piece. If it still in jammed condition, point
it in a safe direction and drop the magazine. Then, still pointing
safely, carefully wiggle the slide to see if you can either clear the
fired case or move the disassembly notch back to allow the slide stop
to be pushed out. If the mag cannot be dropped or if the slide
cannot be moved, then the problem is one for a competent gunsmith.
The pistol must be treated as a loaded, unsafe weapon; if it is at
all possible, bring the smith to the gun, not the other way around.
2. Assuming the jam to have been resolved, begin by clearing in the
usual way to ensure that the gun is unloaded. Field-strip and
inserting a popsicle stick or other thin piece of wood against the
frame to protect it from hammer impact, cock and dry fire to check
lock function. Broken lockwork is for the smith.
3. If the lockwork functions normally, check the ejector for
looseness or breakage. Note its design.
______________________________________________________________________
M1911 Pattern, EJECTOR TYPES
(view from left side)
______________ ________________ _____________
/______________| |_______________| |____________|
|______________| |____________| |__________|
|| || || || || ||
|| || ||
M1911A1 Commander M1911
<---------------- Front of Pistol
______________________________________________________________________
While the pistol can be tuned for perfect function with the stock
M1911A1 ejector, many shooters find that proper ejection function is
possible with a greater variety of loads if an early ("Commander
style") ejector is installed. A stock M1911 ejector works just as
well. Many vendors list such ejectors in Shotgun News. I have found
those manufactured by Wilson to work very satisfactorily. Repair,
removal and replacement of ejectors is possible with home tools, but
directions would be too long for this message.
4. If the ejector is satisfactory, detail strip the slide. The
M1911 extractor is tempered to serve as its own spring. Often,
however, it is assembled without the gentle bend necessary to
supply spring tension. Try reinserting the extractor in its tunnel.
If it is a loose fit, it lacks that tension and will not perform
its function properly. The easiest way of bending it is to
reinsert in a little way into the slide tunnel backwards, so the
tunnel holds it, then grasping the slide, use a pair of needlenose
pliers to give the extractor shank a gentle bend in the direction
in which the extractor hook points.
______________________________________________________________________
M1911 EXTRACTOR
(top view)
Point of contact w. extractor tunnel
\/
__ _______________
______________________/ \_____________| _ |
| __ _____________ _____________ | | |
|_| |___/ \__/ |_________| |__|
|| /\
|| Slide stop cut
\/
Direction of bend
<----Front of pistol (extractor installed)
______________________________________________________________________
When the proper bend is made, the extractor should require moderate
pressure to reinstall in the tunnel, and may be tested as follows:
Reassemble the slide components and lay upside-down. Insert a dummy
round (or, being very careful, a loaded one if a dummy is not
available) into position against the boltface, making sure the
extractor slips into the extraction groove of the case. Then grasp
the slide and, holding in your hand, turn it slowly right side-up. A
properly tensioned extractor should hold a full-weight round in
position, allowing it to droop slightly.
Now, remove the extractor again and check the condition of the hook.
If it is broken or severely chipped, it should be replaced. Even if
it is not, ejection can be compromised by improper hook shape.
______________________________________________________________________
M1911 EXTRACTOR HOOK SHAPE
Side View Front View
______________________ _________
| | | | |
| | | | |
| | | | |
| ' | | '
| / | | /
|' | | .'
----------------------- -
<-----Front of Pistol <-----Ejection Port Side
______________________________________________________________________
The two curved shaping cuts shown are often omitted by manufacturers
of recent-vintage pieces, as they require either either two
additional machine operations or expensive detail work with a casting
mold. If the shaping cut shown at right here is omitted, the square
bottom corner of the hook can hang up in the cartridge extraction
groove during feeding and cause improper cartridge position when the
slide pushes the round forward to chamber.
Absence of the shaping cut shown at left is even more troublesome.
The nominal M1911 ejection algorithm calls for the empty cartridge to
be pulled back by the extractor until it hits the ejector, at which
point it is supposed to pivot off the bottom edge of the extractor
hook and be ejected in a two o'clock direction. If the hook lacks a
rounded edge for the hull to pivot on, the ejector strike will direct
it straight out in a three o'clock direction to hit the inside
surface of the slide. Usually, the case then bounces, hits the top
of the frame, and exits the pistol upward, approaching a twelve
o'clock angle. Sometimes it does not bounce, and ties up the pistol.
With the aid of a strong light, a magnifying glass and a sharp edged
Arkansas stone, the two needed shaping cuts can easily be made at
home. Proper stones can be obtained from Brownell's or from most
well-equipped carpentry supply stores, where they are sold for
sharpening cabinet maker's saws. Instead of making these cuts, some
gunsmiths cure extractor hook ejection problems by cutting away the
slide to lower the ejection port. This expensive machining and
rebluing operation is proper treatment if you reload and need
undented brass. Used as a cure for ejection problems, it is a
confidence trick.
5. Remove the barrel and examine the rear of the chamber and
the rear bottom edge of the hood (the "finger" that sticks back
from the top of the chamber). ASCII fails me here.
a. The back surface of a standard M1911A1 chamber
shows a flat surface, perpendicular to the bore,
with a smallish bevelled scallop cut in the
four o'clock to seven o'clock area. Recent
Colt production barrels have the bevel running
all the way around from two o'clock to about
10 o'clock.
b. The back bottom of the hood should have
a little step machined into it all across its
width. The purpose of this cut is to break the
sharp edge so that a feeding bullet cannot
catch on it. Some second source barrels
lack this cut.
If your chamber edge has the standard M1911 configuration, it is
probably best to confine yourself to FMJ bullets that duplicate the
"hardball" ogive. Some LSWC's can be made to feed with careful
tinkering, but the simplest way to get reliability of anything
other than hardball is to have a pistolsmith "throat" the chamber.
Whether or not you have a throated chamber, place the barrel and link
in the frame and insert the slide stop. Then push the barrel back to
its rearmost position and examine the relation of the chamber edge
and the frame feed ramp. The chamber should stop about 1/16" short
of the beginning of the feed ramp, leaving that much of the saddle
into which the barrel fits showing. If the chamber edge overhangs
the feed ramp, the barrel link lugs are off spec, and that sharp edge
will catch the bullet or case mouth during feeding. Throw the
barrel away.
If the hood edge is not stepped, that can be remedied by a smith, but
making a circular cut is not trivial; see if you cannot buy another
barrel on sale for less money than the pistolsmith will have to
charge you for machine setup.
6. With the barrel out, fit the slide the the frame and move it back
and forth to feel for burrs. Then inspect both slide and frame
visually; sometimes slides feel smooth because they are ridding on
large burrs, and they will become rough when the tips of the burrs
wear away. Unless the piece has had a good accuracy job or several
thousand rounds through it, you are likely to find substantial
burring.
The easiest cure is to detail strip and then, using fine
valve-grinding compound, auto rubbing compound or (my favorite)
jewelers' rouge mixed with light (non-Teflon) machine oil, work the
slide and receiver until smooth. Excess metal removal is
undesirable; it is best to stop frequently, wash the compound off
with solvent and examine progress. About 20 minutes of work is
usually sufficient.
7. Examine the feed ramp in the frame for tool or casting marks. If
you find them, they may be worked on at home. Cratex sells a nice
set of what amount to ink-erasers mounted on Dremel shafts that
polish the ramp nicely. If that is too expensive, a bit of 600 grade
emery paper wrapped around a piece of half-inch dowel will do. The
important thing here is not to change the ramp angle. To the bullet,
a nice shiny tool mark is just as smooth as the lovely mirror finish
that a good smith produces. Don't overdo.
8. Examine the recoil spring guide. It should be polished smooth,
and the mouth should be free of any burrs or projections that could
impede the recoil spring from compressing onto the guide. Most
smiths who work on M1911's have boxes full of these things around
and will sell you one for a buck or so.
9. With smooth slide-receiver movement, you will probably find that
the factory recoil spring is too weak to prevent full-power rounds
from "pounding" the pistol (the feeling is readily recognizable
during firing.) I have found that an 18 1/2 lb. Wolff spring and a
Shok-Buf (a small composition washer that fits on the recoil spring
guide) prevent pistol pounding and allow reliable ejection with a
most loads. While you are buying things, it would not hurt to have a
good Colt magazine. Cartridge presentation angle is critical in the
M1911, and I have had a variety of troubles with second-source
magazines.
10. If you shoot handloads, avoid short LSWC's (Hornaday #4526
and Hornaday #1210 are particularly troublesome) and any load
lighter than about 3.5 grains of Bullseye.
Happy shooting,
_B